The present invention relates to a rotary printing machine which includes a first gearwheel, a second gearwheel, and a setting device for adjusting the second gearwheel relative to the first gearwheel. The setting device selectively adjusts the second gearwheel into a first position, in which the first and second gearwheels are coupled to one another, and into a second position, in which the first and second gearwheels are uncoupled from one another. The printing machine also includes a traction mechanism for securing a staggered-teeth rotary-angle position of the second gearwheel relative to the first gearwheel when the second gearwheel is adjusted into the second position, and a first tension element for tensioning a rotatably arranged traction means of the traction mechanism.
German Patent DE 197 54 544 C1 describes a rotary printing machine with a traction mechanism that although keeping the teeth of the gearwheels staggered when the second gearwheel is adjusted into the second position, does not ensure reliable tooth-flank contact, without tooth play, when the second gearwheel is adjusted into the first position.
It is accordingly an object of the invention to provide a rotary printing machine which overcomes the above-mentioned disadvantages of the prior art apparatus of this general type.
In particular it is an object of the invention to provide a rotary printing machine which corresponds to the generic type initially mentioned and which has a traction mechanism that not only keeps the teeth staggered when the second gearwheel is uncoupled, but also ensures reliable tooth-flank contact, without tooth play, when the gearwheels are coupled to one another.
With the foregoing and other objects in view there is provided, in accordance with the invention, a rotary printing machine, that includes: a first gearwheel; a second gearwheel; a setting device for selectively adjusting the second gearwheel into a first position in which the second gearwheel is coupled with the first gearwheel and into a second position in which the second gearwheel is uncoupled from the first gearwheel; and a traction mechanism for securing a staggered-teeth rotary-angle position of the second gearwheel relative to the first gearwheel when the second gearwheel is adjusted into the second position. The traction mechanism includes rotatably configured traction means. The traction mechanism includes a first tension element for tensioning the traction means. The traction mechanism includes a spring that loads the first tension element. The traction mechanism includes a second tension element assigned to the traction means. The second tension element is mounted to be selectively adjustable into a first switching position and a second switching position.
In accordance with an added feature of the invention, a stop is provided that predetermines the first switching position.
In accordance with an additional feature of the invention, the stop is an adjustable stop.
In accordance with another feature of the invention, a setting drive is assigned to the second tension element; and the setting drive is for adjusting the second tension element into the first switching position and into the second switching position.
In accordance with a further feature of the invention, the setting drive is a pneumatic working cylinder.
In accordance with a further added feature of the invention, the second tension element is a tension roller.
In accordance with a further additional feature of the invention, the traction means rotates along a path; and the first tension element is configured inside the path.
In accordance with yet an added feature of the invention, the traction means has a first portion and a second portion; the first tension element is assigned to the first portion of the traction means; and the second tension element is assigned to the second portion of the traction means.
A particular advantage of the rotary printing machine is the multifunctional use of the traction means. The latter serves both for securing a correct rotary-angle position of the second gearwheel relative to the first gearwheel when the gearwheels are uncoupled from one another, and for bracing the gearwheels with one another when they are coupled.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in Rotary printing machine, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.